Biochemical nutritional parameters and their impact on hemodialysis efficiency

To determine the nutritional status of chronic hemodialysis (HD) patients and the association of changes in serum albumin levels, C-reactive protein (CRP), low density lipoprotein (LDL) cholesterol and body mass index (BMI) as indicators of nutritional status with the urea reduction ratio (URR) during dialysis, we studied 201 chronic HD patients (97 males and the mean age was 51 +/- 15 years). Diabetes was the cause of chronic kidney disease (CKD) in 34% of the patients, hypertension in 57%, chronic glomerulonephritis in 12%, and obstructive uropathy in 10%. BMI less than 18.5 (under weight) was found in 17% of patients, more 18.5 but less than 25 (normal) in 56%, more than 25 but less than 30 (overweight) in 21%, and more than 30 (obese) in 6%. The laboratory investigations revealed hypercalcemia in 62% of the patients (15 patients were found to have tertiary hyperparathyroidism), total cholesterol less than 100 mg/dL in 6% (mean 152 +/- 37.5 mg/dL), and URR of less than 60% in 12% of patients and greater than 60 but less than 65% in 33%. Hypoalbuminemia was associated with poor URR (P < 0.05), whereas no statistically significant correlation was found between URR and iPTH, LDL cholesterol, CRP and body mass index. We conclude that poor nutritional status was detected among a significant number of our patients with poor dietary education. Increased risk of malnutrition was significantly associated with older age and inadequate dialysis dose. Hypoalbuminemia was the single most important factor associated with poor URR.